Testing apparatus



March '14, 1933. S2 E N 1,901,359

TESTING APPARATUS Filed May 6, 1929 JNVENTOR. Z7

ATTORNEY.

fiatented Mar. 14, 1 9 33 UNi'Tsn :s rArEs PATENT orricr.

SAMUEL N. SENNA, or CHICOPEE, mnssncrrusnrrsnssrsivon To B. r. PERKINS & SON,

me, or HOLYOKE, MASSACHUSETTS. A CORPORATION or MAssecHUsErrs TESTING nPrAnA'rUs I Application filed May 6, 1929 Serial No. 360,695.

This invention relates to improvements in testing machines and is directed partlcularly .to improvements in apparatus for testimgpaper and the like by rupturing specimens thereof by pressure.

This invention is particularly adapted for use in connection with testing apparatus of the type shown and described in United States Letters Patent No. 924,625 issued June 10' 8, 1909 and in order to facilitate a clear understanding of the novel features of this invention the apparatus of the patent referred" to will be briefly described.

In this apparatus a specimen of paper or fabric is clamped to a platform provided with a central aperture by a ring-like clamp. A diaphragm ofelastic material below the platform is distended by fluid pressure up through the platform so that-it engages and ruptures the specimen. The pressure of the fluid at the instant of rupture is indicated by a pressure gauge and the indication is taken as the strength of the specimen. The fluid for distending the diaphragm is contained in a chamber and is displaced by a piston either manually operated or-driven from a source of power.

Due to varying temperature conditions,

small leaks in the apparatus stretching of the diaphragm, etc., the amount of fluid in the chamber varies from time to time. This produces unsatisfactory results because in order to obtain the most accurate resultsit is desired to have the chamber completely filled with fluid so that it contacts with the diaphragm at all times. r

Accordingly the novel objects of the invention are directed to theprovisio n of means adapted to be associated with testing appa- 40 ratus of the class referred to which will compensate for any variation in the amount of fluid to the end that more accurate tests may be made. 7

The novel features and advantages of the invention will be observed from the following description of the preferred form thereof, which for illustration purposes are shown in, the accompanying drawing in which:

The figure is a side elevational View partly in section showing a testing machine having the novel features of the invention associated therewith. p

Referring to the drawing in detail the inventi'on will now be described.

A base is shown a t-'2 which is provided witha fluid chamber and a bore or cylin d-er 6 in communication therewith. A 'd iaiphragnrS of flexible stretchable material is clamped to the upper side of the chamber 4: by a platform 10 which is central aperture 12. 1

A piston 14 is movable back and" forth in the bore 6' by a hand wheel 16 which is arranged for rotation as in U. S. Patent 924,625 referred to so that a liquid such as glycerin e5 or'the like in the chamber may be displaced to distend the diaphragm upwardly through the aperture in the platform 10.

' A clamp 18 at the end of arod 20 in threadmay be indicated by a pressure gauge and the pressure reading taken as the designation of the strength of the nary practice. a I

As has been stated the amount of liquid in the chamber causes and the amount be decreased so? that it does not contact with the under side of the diaphragm when the piston 'is in retracted position, which is objectionable. Further more may bedesirable to provide sufficient 90 provided with a 60 paper. This is ordimay varydue to various liquid to distend the diaphragm while the piston is in retracted position so that its upper side is normally level with the surface of the platform. It will be appreciated that the addition of liquid is accomplished ordinarily by removing the platform and diaphragm wh reby it is difiicult if not impossible to add the exact amount desired.

According to the novel features of the invention, I provide the means now to be described for displacing fluid so that the chamber will be filled to the extent desired.

A pump P consisting of a body which is provided with a central chamber or bore 80' haspassageways and 3a in communication therewith. he passageway 32 is connected to the chamber 4i of the body 2 while the other passageway ea is connected to a pressure in dicating gauge G of well known form- The upper end of the bore of the body 80 is closed by plug 38 in threaded engagement therewith and a valve plug 40 of usual form is provided which is rotatable in the body below the said plug.

A. piston 4a engagement with the body is moved back and forth along the bore by screwing the rod in and out of the body. A hand wheel 48 is lined to the rod to facilitate the turning of the rod so as to movethepiston back and forth along the bore. As will be seen the chamber, pump and. gauge are interconnected.

In operation with a liquid in the chamber and pump the piston 44 may be moved back and forth along the bpre to displace the carried by a rod 46 in threaded SAM L N. SENNA.

liquid so that it fills up the chamber and engages the'un der side of the diaphragm. In

' this way it is possible to insure that the chamher is at all times filled with liquid. When it is desired to distend the diaphragm so that it is flush with the platform 10 when the piston 14 is in its'retracted position, it is only necessary to displace the liquid by moving the piston la upwardly Within the bore of the pump.

With the chamber thus filled to the extent desired, the test may be carried out by moving the piston 14- inwardly so as to displace the liquid and distend the diaphragm and rupture the specimen. The pressure attained is communicated of coursethrough passageways 32 and34l to the pressure gauge for the purpose described.

From the foregoing it will be observed that Ihave provided means in communication with the chamber which is operable independently of the piston for displacing'the liquid therein whereby it is possible to vary the amount of liquid in the chamber as is desirable for most accurate results.

Having described the invention in the form at present preferred what I desire to claim and secure by Letters Patent is Testing apparatus of the class described 

